Linear vibration motor

ABSTRACT

A linear vibration motor is disclosed. The linear vibration motor includes a housing, a vibrator placed in the housing and an elastic component providing the vibrator with restoring force of vibration. The linear vibration motor also comprises a guide device including an internal guide device, an external guide device, a ball location device arranged between the internal guide device and the external guide device and moving opposite to the housing, and multiple balls positioned on the ball location device. The balls are propped against the external guide device and the internal guide device respectively. Moreover, the rollers will roll in presence of drive effect of the internal guide device and roll at the permanent position. The vibrator is propped in the housing by using the balls.

FIELD OF THE INVENTION

The present disclosure is related to motors, specifically to a linearvibration motor for converting electric signals to mechanical vibrationwhich is sensible for human body.

DESCRIPTION OF RELATED ART

A vibration motor shall be applied to feedback of system generally, forexample, incoming call prompt of mobile phone, vibration feedback ofgame player, etc. for the portable consumer electronic products, such asa mobile phone, a handheld game player, a navigation unit or a handheldmultimedia entertainment equipment; and the motor used mainly refers toseveral types, such as columnar core motor, coreless motor and flatvibration motor.

All kinds of components of the internal part thereof are required toadapt to the trend of light and thin along the development direction oflight and thin consumer electronic products. The motor is not ofexception.

A linear vibration motor is characterized in that the vibrationdirection of the vibration unit refers to straight reciprocating motionand has been applied and installed on the consumer electronic productswidely because of stable vibration and small noise thereof. Please referto Chinese patent application No.: CN200480000815.4 publicized on Nov.23, 2005, U.S. Pat. No. 6,466,682 publicized on Oct. 15, 2002, U.S. Pat.No. 7,099,489 publicized on Aug. 29, 2006, etc.

However, the vibration direction of the vibration unit of the saidvibration motor involves the vertical direction, that is, vertical tothe installation plane; and great vertical height is required to providebecause the vibration direction is vertical to the installation plane inorder to facilitate up-and-down motion of the vibration unit andincrease the height of the whole motor. Yet, it is not useful fordevelopment of thin motor.

On this basis, the vibration motor with vibration direction vertical tothe thickness direction of the device where the vibration motor islocated was studied. For example, the Chinese patent application No.:200910105497.2 publicized on Jul. 22, 2009 disclosed the vibration motorof suspending the vibrator in the housing by using the spring component,wherein the problem that the said vertical vibration motor requiredgreat vibration space was solved excellently by setting the vibrationdirection of the vibrator parallel with the installation surface of thevibration motor (transverse vibration) by using the magnetic circuit andthe coils set in advance.

The vibrator of the said transverse vibration motor was suspended byusing the spring component, and the spring component received theelastic restoring force offered to the vibrator through extrusion andreleasing continuously during vibrating process of the vibrator.However, the sense of vibration was reduced because the vibratorvibrated transversely during vibrating process due to flaky structure ofthe spring component and cannot move excellently along the straight lineas a result of reversion of the elastic deformation of the springcomponent.

Therefore, it is necessary to provide a new linear vibration motor toovercome the problems mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiment can be better understood with referenceto the following drawings. The components in the drawings are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present disclosure. Moreover,in the drawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is an isometric view of a linear vibration motor in accordancewith an exemplary embodiment of the present disclosure.

FIG. 2 is a top view of the linear vibration motor in FIG. 1, wherein acover of the linear vibration motor is removed in order to facilitateviewing.

FIG. 3 is an isometric view of an external guide device of a guidedevice of the linear vibration motor in FIG. 1.

FIG. 4 is an isometric view of an internal guide device of the guidedevice of the linear vibration motor in FIG. 1.

FIG. 5 is an isometric view of a ball location device of the guidedevice of the linear vibration motor in FIG. 1.

FIG. 6 is an isometric view of an assembly of the external guide device,the internal guide device and the ball location device in FIGS. 3-5.

FIG. 7 is a cross-sectional view of the linear vibration motor takenalong Line VII-VII in FIG. 2.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

The present invention will hereinafter be described in detail withreference to an exemplary embodiment. To make the technical problems tobe solved, technical solutions and beneficial effects of presentdisclosure more apparent, the present disclosure is described in furtherdetail together with the Figs. and the embodiment. It should beunderstood the specific embodiment described hereby is only to explainthis disclosure, not intended to limit this disclosure.

A linear vibration motor 100, in accordance with an exemplary embodimentof the present disclosure, is shown in the FIG. 1 and comprises a cover11 and a housing 12 forming the accommodation space with the cover 11,as well as a conducting end 20 connecting with the external circuit inorder to receiving the external electric signal.

In the embodiment, the housing is formed by a cover 11 and a housing 12which can be set by using other mode according to differentmanufacturing processes or assembling processes, for example, the cover11 and the housing 12 can be formed integrally, or the cover 11 has thestructure of the housing 12, or the housing 12 has the structure of thecover 11. In short, the housing formed by the cover 11 and the housing12 shall offer a accommodation space to accommodate other components ofthe linear vibration motor 100 therein. As for the materials of thecover 11 and the housing 12, the available material of the linearvibration motor, or metal, or plastic, or mixture of the metal and theplastic can be adopted. What shall be explained is that the so-calledhousing shall involve both appearance components forming the linearvibration motor 100, appearance components and other components whichare fixed with respect to the appearance components. Further, thehousing can be the stator in the vibration motor; and the so-calledstator shall involve the components (such as housing, the cover) or setof the components (except other components of the vibrator) which isimmobile with respect to the installation location of the linearvibration motor.

The structure of the internal part of the accommodation space isdisplayed in the FIG. 2 clearly, and the cover 11 has been removed. Inview of the long-strip housing, the components of the internal partshall be shaped as long strips approximately. The internal componentsinclude a vibrator 13, a guide device 14 suspending the vibrator 13, andan elastic component 30 providing the vibrator 13 with elastic restoringforce. The vibrator 13 further comprises a mass 131 and a drive device132 assembling and connecting with the mass 131. In the embodiment, themass 131 is located on one end of the drive device 132, that is, both ofthem are located on two ends of the vibrator 13. Actually, the drivedevice 132 is used for driving vibrations of the whole vibrator 13, andthe mass 131 is used for improving the amplitude by increasing thedriving force; therefore, the positional relationship of the two partsis not limited to what is shown in FIG. 2, and can be arranged in theforms of other structures, for example, the mass includes two parts,while the drive device is arranged among the two masses; or the drivedevice includes two parts, and the mass is arranged among the two drivedevice; and the said structures are feasible. What shall be explained isthat the elastic component 30 can be spring, leaf spring or otherdevices which can be compressed and released, such as compressed airdevice, magnetic attracting/repelling device, etc.

Further, the drive device 132 includes a magnet 132 a and multiple coils132 b surrounding the magnet 132 a. Moreover, see contents in backgroundtechnology of the parent application document or the technical contentof the available parent quoted in the background technologies forinteraction of the magnet and the coils of the transverse linearvibration motor, and the embodiment shall not repeat it any longer.

The guide device 14 comprises an external guide device 141, a balllocation device 142, an internal guide device 143 and multiple balls144. The external guide device 141 is fixed in the housing 12 and is onepart of the housing in this embodiment, or not one part of the housingin other feasible shape, for example, being installed at the internalpart of the accommodation space of the housing, or on the stator of thevibration motor. The ball location device 142 is applied to limitationof locations of multiple balls 144, that is, the locations of the balls144 are immobile relatively on the ball location device, except rollingof the balls of course. The internal guide device 142 is fixed on themass 131 and the ball location device 142 is arranged between theinternal guide device 142 and the external guide device 141 in the wayof clamping; and the so-called installation in the way of clamping shallpurely involve the positional relationship, rather than the combiningrelationship of the two devices, that is, the ball location device 142is arranged between the external guide device 141 and the internal guidedevice 143. At the same time, the ball location device 142 is moveablewith respect to the stator. The external guide device 141 is fixed onthe housing and the internal guide device 143 is fixed on the mass 131(or on the vibrator 13) in the embodiment. Therefore, the external guidedevice 141 is combined with the stator actually, while the internalguide device 143 is combined with the vibrator. The guide device 14shall be optionally arranged at a center of gravity of the vibrator 13or the place nearby in order to support the vibrator 13 stably andprovide stable vibration locus. The balls 134 pass through the balllocation device 142 and the part of the same located on two sides of theball location device 142 is propped up the external guide device 141 andthe internal guide device 143. When the vibrator 13 vibrates, theinternal guide device 143 shall vibrate with the vibrator; while theballs 144 shall roll in the internal guide device 143 oppositely. Theball location device 142 may slide along vibration direction of thevibrator as a result of friction force between the internal guide device143 and the balls because the locations of the balls 144 shall bechanged along vibration of the vibrator due to relatively moveablelocation of the ball location device 142. Therefore, the external guidedevice 141 and the internal guide device 143 may implement friction ofrolling with respect to the balls. Moreover, a limitation devices 121arranged on two ends of the ball location device respectively arearranged on the vibration direction of the vibrator 13 in order to limitseparation from the cooperation between the ball location device and theexternal guide device 141 and the internal guide device 143 duringsliding and prevent the ball location device from collision with themass during sliding, and therefore, the displacement of the balllocation device shall be limited by the limitation device 121 duringsliding.

The isometric view of the external guide device 141 is shown in FIG. 3,and the external guide device 141 comprises a first side wall 141 a anda second side wall 141 b which are opposite to each other, and a bottomball 141 c connecting one end of the first side wall 141 a and thesecond side wall 141 b. A first guide slot 141 d is provided on thefirst side wall 141 a while a second guide slot 141 e is provided on thesecond side wall 141 b. Moreover, the first side wall 141 a and thesecond side wall 141 b are located on two sides of the vibrator 13respectively and are immobile with respect to the stator after beingassembled as shown in FIG. 7.

The isometric view of the internal guide device 143 is shown in FIG. 4,and the internal guide device 143 comprises a main body 143 a and aninternal guide slot 143 b arranged on the main body 143. The linearvibration motor has two internal guide devices 143 which are located ontwo sides of the vibrator and corresponding to the first side wall 141 aand the second side wall 141 b of the external guide device (referringto FIG. 7). Of course, the internal guide device, like the externalguide device, can be formed as the integral structure having the bottomwall as long as the vibrator has the structure corresponding to theexternal guide device. Similarly, the external guide device may have twoindependent components which are fixed on the housing or the statorrespectively and will not affect the moving relationship with theinternal guide device.

The isometric view of the ball location device 142 is shown in FIG. 5,and the ball location device 142 comprises a first location wall 142 aand a second location wall 142 b which are opposite to each other and aconnecting wall 142 c connecting the first location wall and the secondlocation wall. At the same time, multiple location holes 142 d areprovided on the first location wall 142 a and the second location wall142 b. As previously mentioned, the ball location device 142 may includetwo independent components but not have the connecting wall 142 c.

As shown in FIG. 6 and FIG. 7, the first location wall 142 a ispositioned between the internal guide device 143 and the first side wall141 a, and the second location wall 142 b is positioned between theinternal guide device 143 and the second side wall 141 b when theexternal guide device, the internal guide device and the ball locationdevice are assembled together. The ball 144 is arranged in a firstlocation hole 142 d of the first location wall 142 a, one end of thesame shall be accommodated in the first guide slot 141 d of the externalguide device, and the other end of the same shall be accommodated in theinternal guide slot 143 b of the internal guide device. Further, theball 144 is arranged in the second location hole 142 e of the secondlocation wall 142 b, one end of the same shall be accommodated in thesecond guide slot 141 e of the external guide device, and the other endof the same shall be accommodated in the internal guide slot 143 b ofthe internal guide device. A gap is reserved between the bottom of thevibrator and the connecting wall 142 c of the ball location device inorder to facilitate vibration. Further, the positional relationship ofthe balls and the ball location device will not be changed because theball location device is moveable opposite to the stator, while theopposite positions of the ball and the external guide device and theopposite position of the ball and the internal guide device will bechanged along vibration of the vibrator. Moreover, rolling frictionoccurs between the external guide device and the ball and the internalguide device and the ball with minimum friction force; therefore, thevibrator can vibrate smoothly.

The balls and the ball location device can be driven to roll by theinternal guide device during vibrating process of the vibrator. Theballs may roll in the guide slot of the external guide device and theinternal guide slot of the internal guide device during movement of theball location device because the location of the ball location device ismoveable with respect to the stator or the housing. Therefore, thevibrator is suspended in the housing by the balls actually and vibratesalong extension direction of the guide slot and the internal guide slot.In this way, the vibration direction of the vibrator is limited in theextension direction of the guide slot and the internal guide slot.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present embodiment have been setforth in the foregoing description, together with details of thestructures and functions of the embodiment, the disclosure isillustrative only, and changes may be made in detail, especially inmatters of shape, size, and arrangement of parts within the principlesof the invention to the full extent indicated by the broad generalmeaning of the terms in which the appended claims are expressed.

What is claimed is:
 1. A linear vibration motor including: a housing, avibrator placed in the housing; an elastic component providing thevibrator with restoring force; a guide device, including: an internalguide device fixed on the vibrator, an external guide device fixed onthe housing corresponding to the internal guide device, a ball locationdevice arranged between the internal guide device and the external guidedevice, the ball location device being movable along a vibrationdirection of the vibrator; a plurality of balls positioned on the balllocation device, the balls abutting against the external guide deviceand the internal guide device respectively by passing through two sidesof the ball location device; the guide device is positioned at thecenter of gravity of the vibrator.
 2. The linear vibration motoraccording to claim 1, wherein the external guide device is one part ofthe housing.
 3. The linear vibration motor according to claim 1, whereinthe internal guide device is one part of the vibrator.
 4. The linearvibration motor according to claim 1, wherein the external guide devicecomprises a first side wall and a first guide slot arranged on the firstside wall; and correspondingly, the internal guide device is equippedwith a main body and an internal guide slot arranged on the main body;the ball location device comprises a first location wall correspondingto the first side wall and a plurality of location holes arranged on thefirst location wall; the balls are placed in the first location holes,and parts of the balls positioned on two sides of the first locationwall are accommodated in the first guide slot and the internal guideslot, respectively.
 5. The linear vibration motor according to claim 4,wherein the external guide device comprises a second side wall and asecond guide slot arranged on the second side wall; the second side walland the first side wall are positioned on two sides of the vibrator,respectively; correspondingly, the ball location device includes asecond location wall corresponding to the second side wall and multiplesecond location holes arranged on the second location wall; the ballsare placed in the second location holes; the internal guide device isinstalled opposite to the internal guide device and on other side of thevibrator; and the parts of the balls positioned on two sides of thesecond location all are placed in the second guide slot and the internalguide slot of the internal guide device, respectively.
 6. The linearvibration motor according to claim 1 further comprising a limitingdevice fixed on the housing for limiting moving range of the balllocation device.
 7. The linear vibration motor according to claim 6,wherein the limiting device is positioned on two ends of the balllocation device.
 8. The linear vibration motor according to claim 5,wherein the first side wall is connected with the second side wall by abottom wall.
 9. The linear vibration motor according to claim 5, whereinthe first location wall is connected with the second location wall by aconnecting wall.